<template>
      <footer class="footer">
      <!-- This should be `0 items left` by default -->
      <span class="todo-count">剩余<strong>{{residue}}</strong></span>
      <!-- Remove this if you don't implement routing -->
      <ul class="filters">
        <li>
          <a href="#/" @click="$emit('changeFlag', 'a')" :class="{selected: flag === 'a'}">全部任务</a>
        </li>
        <li>
          <a href="#/active" @click="$emit('changeFlag', 'b')" :class="{selected: flag === 'b'}">进行中</a>
        </li>
        <li>
          <a href="#/completed" @click="$emit('changeFlag', 'c')" :class="{selected: flag === 'c'}">已完成</a>
        </li>
      </ul>
      <!-- Hidden if no completed items are left ↓ -->
      <button class="clear-completed" @click="$emit('delCompleted')">清除已完成</button>
    </footer>
</template>

<script>
export default {
  props: {
    list: Array,
    flag: String
  },
  computed: {
    residue () {
      return this.list.filter(item => item.isDone === false).length
    }
  }
}
</script>

<style>

</style>